Carb Problem

[bigred shrtbd]

My truck had a wimpy 2 barrel on it so I dropped a 4 barrel quadrajet on it, then after a couple days that went to crap b/c it was on its last leg, Now I put another one on it and all day it ran Real nice and strong but tonite i went to start it up and it is running ****ty once again, i mean it just sits there and idles extremely rough and it will not stay running unless u are continously on the throttle. it is like its flooding itself out b/c there is a extreme amount of smoke. part of the choke is not hooked up b/c i have a 78 intake manifold and a 76 carb and the chokes are diff. So maybe thats it but im tottally lost on what to do please help

 

[jimmyjack]

could be a vacuum leak or a stuck or sunken float. I'd bet the float is the problem.

 

[justhorsinaround]

I'll agree. Check the floats and the needle valve. Before you go and tear the thing out though, take a peek down the throat and see if you can see gas pourin in the engine. If it's not start thinkin vacuum leak.

Good luck to ya in the future.

Allan

 

[R72K5]

its really hard to say without seeing/hearing it, it could be choke related or it might not be, have no idea,

if the choke is wired open then it will run like junk til its halfway warmed up, if its shutting on you then it will run rich and smoke black and rnu like junk when halfway warm and after, or even when is cold if is completely shut,

might not even be a carb issue at all, have no clue, might be ignition problem


i would find someone who is a sbc guru and have them tune it all up for you

if you can find a vacuum guage to borrow real quick then connect it to the intake somewhere and check that the vacuum is between 18 and 22 and that the needle doesnt move around at idle or at a steady rpm around 1500 or 2k

if needle is jumpy then something else is wrong suich as vacuum leak somewhere or valvetrain problem, IE improperly adjusted rockers or bad lifter or cam lobe, etc

 

[bryguy00b]

i had the same problem with the quadrajet i just took off my truck, did just that. would run fine then all of the sudden start flooding out, running incredibly rich and shitty and smokin like a train. i think the floats or needles in it are just messed up.but i just swapped another one on there a guy gave me and i have to go fool with it. i started it up real quick last night and it was running high and rough and backfiring, im guessing and hoping its juts a vacum leak..i have a few ports that need to be block of anyway..

 

[pauly383]

My original one did that , was dirt (from charcoal in air cleaner or canister) in there keeping rods from seating in jets. I ended up replacing my carb anyway, as soon as I fixed it, it still sucked air around throttle shafts. New run runs great /forums/images/graemlins/k5.gif

 

[bigred shrtbd]

yea Im pretty sure its the floats but what really pisses me off is that ive had 3 carbs on this thing, but again all old ones. but still ran good at one time.So this is my theroy becuz the trucks sat for a long time I put bout $10.00 in gas in the tank. which I think mite of knocked around some crud and which in turn got into the carb plus I just discovered that all the carbs had no fuel filters on them so they made the floats and neddles stick. becuz after a while gas will start comming outta the throttle rod and top of the carb.

 

[pauly383]

Yup , no filter will do it to ya. Ten bucks is like 5 gallons if your lucky where I'm at, wouldn't doubt there was dirt sucked in. I actually run the stock filter for simplicity, and since I change all my filters way too often I haven't worried about it for a looooong time. You may want to throw a quick rebuild on it. Its pretty easy. /forums/images/graemlins/k5.gif